Electrode system

ABSTRACT

An electrode system comprises electrode modules, flexible connectors, and sensors. Each electrode module defines a substantially central opening and has circuitry that includes an amplifier. A conductive ring is exposed in the opening of each electrode module. The flexible connectors include flexible circuitry coupled with the circuitry of the electrode modules. Each sensor includes an electrolytic hydrogel portion that is configured to contact a test subject and outwardly extending tabs that are in communication with the hydrogel portion, The tabs are configured to contact the conductive ring of an electrode module with the sensor is inserted in the opening of the electrode module. The system may thus sense evoked response potentials (ERPs) from the test subject through the electrolytic hydrogel portions, amplify those potentials, and communicate the amplified potentials through the circuitry of the flexible connectors. A control box may initiate ERP testing and store the test results.

PRIORITY

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/114,715, filed Nov. 14, 2008, entitled “Electrode System,”the disclosure of which is incorporated by reference herein,

BACKGROUND

In some settings, it may be desirable to position a headset withelectrodes on a test subject's head, such as to test the subject forvarious conditions, including but not limited to various types ofdiseases or conditions within the cerebral cortex, Alzheimer's,Parkinson's, dyslexia, autism, and/or schizophrenia, among otherconditions. For instance, one or more system components may be used toprovide one or more types of stimuli to the test subject (e.g.,auditory, visual, and/or tactile stimulus, etc.); and electrodes may beused to detect Evoked Response Potentials (ERP's) associated with suchstimuli, By way of example only, active or locally amplified electrodes,as well as related systems and methods, are discussed in the followingdocuments, each of which is incorporated by reference herein: U.S. Pat.No. 5,479,934, entitled “EEG Headpiece with Disposable Electrodes andApparatus and System and Method for Use Therewith,” issued Jan. 2, 1996;U.S. Pub. No. 2005/0215916, entitled “Active, Multiplexed DigitalElectrodes for EEG, ECG, and EMG Applications,” published Sep. 29, 2005;U.S. Pub. No, 2007/0106169, entitled “Method and System for an AutomatedE.E.G. System for Auditory Evoked Responses,” published May 10, 2007;U.S. Pub. No. 2007/0270678, entitled “Wireless Electrode forBiopotential Measurement,” published Nov. 22, 2007; and U.S. Pub. No,2007/0191727, entitled “Evoked Response Testing System for NeurologicalDisorders,” published Aug. 16, 2007. Copies of those documents are alsoappended hereto. It should be understood that the teachings herein maybe applied to or otherwise combined with any of the systems and methodstaught in all of the above-cited documents.

While a variety of electrode systems have been made and used, and whilea variety of methods have been used to construct such electrode systems,it is believed that no one prior to the inventor(s) has made or used aninvention as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

It is believed the present invention will be better understood from thefollowing description of certain examples taken in conjunction with theaccompanying drawings, in which like reference numerals identify thesame elements and in which:

FIG. 1 depicts a perspective view of an exemplary ERP testing system;

FIG. 2 depicts a top plan view of electrode components of the ERPtesting system of FIG. 1;

FIG. 3 depicts a rear elevational view of the electrode components ofFIG. 2;

FIG. 4 depicts a top plan view of an electrode module of the electrodecomponents of FIG. 2;

FIG. 5 depicts an exploded perspective view of the electrode module ofFIG. 4, with an exemplary sensor;

FIG. 6 depicts a top plan view of the electrode module of FIG. 4, with atop housing component and flex circuit component removed;

FIG. 7 depicts a cross-sectional side view of the electrode module ofFIG. 4, taken along line 7-7 of FIG. 4;

FIG. 8 depicts a perspective view of an exemplary sensor for use withthe ERP testing system of FIG. 1; and

FIG. 9 depicts an exploded view of the sensor of FIG. 8.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the invention may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presentinvention, and together with the description serve to explain theprinciples of the invention; it being understood, however, that thisinvention is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the invention shouldnot be used to limit the scope of the present invention. Other examples,features, aspects, embodiments, and advantages of the invention willbecome apparent to those skilled in the art from the followingdescription, which is by way of illustration, one of the best modescontemplated for carrying out the invention. As will be realized, theinvention is capable of other different and obvious aspects, all withoutdeparting from the invention. Accordingly, the drawings and descriptionsshould be regarded as illustrative in nature and not restrictive.

Exemplary System Overview

As shown in FIG. 1, an exemplary electrode system (10) includes aheadset (20) and a control box (40). Headset (20) comprises a head frame(24) and a plurality of electrode modules (100). While headset (20) ofthe present example comprises eight electrode modules (100), it shouldbe understood that any other suitable number of electrode modules (100)may be used. It should also be understood that the arrangement ofelectrode modules (100) shown in FIGS. 1-3 is merely exemplary; and thatelectrode modules (100) may be positioned in any other suitablearrangement. Electrode modules (100) are removably coupled with headframe (24) as will be described in greater detail below.

Exemplary Head Frame

In the present example, head frame (24) is formed of several resilientstraps (26), and electrode modules (100) are secured to head frame (24)at junctions of resilient straps (26). The junctions of resilient straps(26) comprise annular snap members (28), which are each open at theircenter. As will be described in greater detail below, openings (106) ofelectrode modules (100) are configured to align with the open centers ofcorresponding snap members (28), to allow inserted sensors (200) tocontact the test subject's head. In some versions, resilient straps (26)are formed of elastic, though it should be understood that any othersuitable material or combination of materials may be used. While headframe (24) of the present example is configured to substantiallyencompass a test subject's head, it should also be understood that headframe (24) may have any other suitable configuration. By way of exampleonly, head frame (24) may comprise a EzeNet® reusable head piece byHydroDot, Inc. of Westford, Mass. A EzeNet® reusable head piece may comein various sizes and conform to the international 10/20 system ofelectrode placement.

As another merely illustrative example, head frame (24) may beconfigured and/or operable in accordance with the teachings of U.S. Pub.No. 2007/0191727, entitled “Evoked Response Testing System forNeurological Disorders,” published Aug. 16, 2007, the disclosure ofwhich is incorporated by reference herein; and/or in accordance with theteachings of any other document cited herein. Indeed, various ways inwhich the teachings herein may be combined with the teachings of U.S.Pub. No. 2007/0191727 and/or the teachings of any other document citedherein will be apparent to those of ordinary skill in the art.Alternatively, head frame (24) may have any other suitable configurationand/or operability. Other suitable variations of head frame (24) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

As shown in FIGS. 1-3, electrode modules (100) are physically andcommunicatively coupled with each other via flexible connectors (50).Electrode modules (100) are also physically and communicatively coupledwith a control box interface module (30) via flexible connectors (50).Flexible connectors (50) of the present example comprise flexiblecircuits, which comprise traces (not shown) formed in a flexiblesubstrate. Alternatively, conventional wires or other conduits may beused. In the present example, headset (20) is coupled with control box(40) via cables (42). In particular, control box interface module (30)includes ports (32), with which cables (42) may be coupled. Control boxinterface module (30) also includes circuitry configured to routesignals between flexible connectors (50) and cables (42) via ports (32).Control box interface module (30) may thus provide a communicativeinterface between cables (42) and flexible connectors (50). Varioussuitable components that may be incorporated into control box interfacemodule (30), as well as various suitable features/functionalities ofsuch components, are described in the documents cited herein. By way ofexample only, control box interface module (30) may be constructed andoperable in accordance with the headset “control module 12” teachings ofU.S. Pub. No. 2007/0191727 and/or the teachings of any other documentcited herein. Still other suitable components that may be incorporatedinto control box interface module (30) will be apparent to those ofordinary skill in the art in view of the teachings herein.

In the present example, and as shown in FIG. 2, control box interfacemodule (30) also includes flanged members (34). Flange members (34) areconfigured to secure control box interface module (30) with head frame(24). For instance, head frame (24) may include openings that areconfigured to receive flanged members (34). Of course, control boxinterface module (30) may be secured to head frame (24) in a variety ofother ways as will be appreciated by those of ordinary skill in the art,to the extent that control box interface module (30) is secured to headframe (24) at all. Furthermore, control box interface module (30) maysimply be omitted in some versions (e.g., cables (42) couple directly tofreely hanging flexible connectors (50), etc.).

Exemplary Control Box

Control box (40) of the present example includes a storage medium (notshown) that is configured to store various testing protocols (e.g., ERPtesting protocols, etc.); and a processor (not shown) that is configuredto execute such testing via headset (20). In particular, control box(40) provides power and commands or other types of signals to headset(20) via cables (42) in the present example; while headset (20)transmits data or other types of signals back to control box (40) viacables (42). Control box (40) is also operable to store data collectedduring such testing, including but not limited to data obtained throughelectrode modules (100). Such power, commands, data, or other types ofsignals may be provided in accordance with various types of ERP testingprotocols as described herein and as described in the documents that areincorporated by reference herein.

Control box (40) is configured to be coupled with a computer system (notshown) via wire and/or wirelessly. For instance, a computer system maytransmit testing protocols, commands, or other data to control box (40).Similarly, control box (40) may transmit commands, test results, orother data to a computer system. Control box (40) of the present exampleis also configured to be handheld. By way of example only, control box(40) may be held in the hand of the test subject who is wearing headset(40), in the hand of a clinician or nurse, or in the hand of any otherperson, In addition to or in lieu of the foregoing, control box (40) maybe configured in accordance with, operable in accordance with, and/orpossess any suitable features/functionalities of similar componentsdescribed in any of the documents cited herein, including but notlimited to U.S. Pub. No. 2007/0191727. Various ways in which theteachings herein may be incorporated into or otherwise combined with theteachings of the documents that are cited herein will be readilyapparent to those of ordinary skill in the art.

While two cables (42) are shown, it should be understood that just onecable (42) may be used. It should also be understood that some otherversions of electrode system (10) may provide communication of power,commands, data, and/or other types of signals to and/or from headset(20) wirelessly, in addition to or in lieu of having cables (22).

Exemplary Electrode Module

In the present example, electrode modules (100) of electrode system (10)are substantially identical to each other. The following descriptionwill therefore just describe an individual electrode module (100) as anexample. It should be understood, however, that a given electrode system(10) may have different types of electrode modules (100). In otherwords, one or more electrode modules (100) within a given electrodesystem (10) may have features, components, functionalities, etc., thatdiffer from the features, components, functionalities, etc., of otherelectrode modules (100) within the same electrode system (10). Suchdifferences among electrode modules (100) may be based on a variety ofconsiderations, including but not limited to the location of electrodemodule (100) on the test subject's head or other part of the testsubject's anatomy. Suitable ways in which electrode modules (100) maydiffer from each other within a given electrode system (10) will beapparent to those of ordinary skill in the art in view of the teachingsherein. Alternatively, as in the present example, all electrode modules(100) within a given electrode system (10) may be substantiallyidentical to each other.

As shown in FIGS. 2-7, electrode module (100) comprises an upperclamshell member (102), a lower clamshell member (104), a circuit board(130), and a conductive ring (150). Clamshell members (102, 104) may beformed of molded plastic and/or using any other suitable material(s)and/or process(es). As shown, upper clamshell member (102), lowerclamshell member (104), circuit board (130), and conductive ring (150)all define a central opening (106). In particular, the central openingsof upper clamshell member (102), lower clamshell member (104), circuitboard (130), and conductive ring (150) are all configured to coaxiallyalign when these components are assembled together to form electrodemodule (100), such that the assembled electrode module (100) itselfdefines a central opening (106). This central opening (106) isconfigured to insertingly receive a sensor (200) as will be described ingreater detail below. In addition, these components are configured suchthat a portion of conductive ring (150) is exposed in the inner diameterof the central opening (106) of the assembled electrode module (100), aswill also be described in greater detail below. During assembly ofelectrode module (100), upper clamshell member (102) may be secured tolower clamshell member (104) using any suitable technique or techniques,including but not limited to ultrasonic welding, snap-fitting,adhesives, fasteners, etc. While opening (106) is at the approximatecenter of electrode module (100) in the present example, it should beunderstood that opening (106) may be located off-center or otherwiserelative to the remainder of electrode module (100).

Upper clamshell member (102) of the present example presents an annularinclined surface (108) at the perimeter of opening (106). Annularinclined surface (108) is configured to facilitate insertion of sensor(200) into opening (106) as will be described in greater detail below.Of course, as with other components and features described herein,inclined surface (108) is merely optional. Lower clamshell member (104)of the present example comprises a first pair of upwardly extendingposts (110) and a second pair of upwardly extending posts (112). Lowerclamshell member (104) also includes an annular rim (114) at theperimeter of opening (106) and a trench (116) adjacent to annular rim(114). Each of these features of lower clamshell member (104) will bedescribed in greater detail below.

Circuit board (130) of the present example comprises a pair of openings(132) and a pair of connectors (134). As shown in FIGS. 5-6, openings(132) of circuit board (130) are configured to align with and receiveposts (110) of lower clamshell member (104). Openings (132) and posts(110) may thus assist in properly registering circuit board (130) withlower clamshell member (104) and assist in securing circuit board (130)relative to lower clamshell member (104). Of course, openings (132) andposts (110) are merely one of many different ways in which circuit board(130) may be registered and secured relative to lower clamshell member(104). Various other structures, features, techniques, etc. forregistering and/or securing circuit board (130) relative to lowerclamshell member (104) will be apparent to those of ordinary skill inthe art in view of the teachings herein.

Connectors (134) of circuit board (130) are configured to be physicallyand communicatively coupled with flexible connectors (50). Inparticular, each connector (134) has a slot that is configured toreceive a free end of a corresponding flexible connector (50). Flexibleconnector (50) has an opening (52) that is configured to receive a post(112) of lower clamshell member (104). Thus, when flexible connector(50) is inserted in the slot of connector (134), with post (112)inserted through opening (52) of flexible connector (50), and whenclamshell members (102, 104) are secured relative to each other as shownin FIG. 7, the insertion of post (112) through opening (52) maysubstantially prevent flexible connector (50) from being pulled out ofconnector (134). In addition, connector (134) may have one or moreexposed/exposable electrical contacts within its slot; while the freeend of flexible connector (50) may have one or more correspondingelectrical contacts that are positioned to contact the one or moreexposed/exposable electrical contacts within the slot of connector(134). Connector (134) may thus communicate power, commands, data, othersignals, etc., to and/or from one or more traces of flexible connector(50).

Of course, connectors (134) are merely optional, and connectors (134)may be modified, substituted, supplemented, or omitted as desired. Byway of example only, some alternative versions omit connectors (134)entirely by forming all flexible connectors (50) and circuit boards(130) as a single, unitary rigid-flex circuit. A merely illustrativeexample of such a rigid-flex circuit is disclosed in U.S. ProvisionalPatent Application Ser. No. 61/245,686, entitled “Electrode System withRigid-Flex Circuit,” filed Sep. 25, 2009, the disclosure of which isincorporated by reference herein. Still other suitable ways in whichconnectors (134) may be modified, substituted, supplemented, or omittedwill be apparent to those of ordinary skill in the art in view of theteachings herein.

As shown in FIGS. 1-3 and as noted above, electrode modules (100) arecoupled via flexible connectors (50). In some versions, differentelectrode modules (100) have their own dedicated traces along suchflexible connectors (50). Dedicated traces for a given electrode module(100) may run along part of the same length of flexible connectors (50)as dedicated traces for another given electrode module (100). Forinstance, a set of dedicated traces for one electrode module (100) maybe provided on one layer of flexible circuitry in a given flexibleconnector (50); while a set of dedicated traces for another electrodemodule (100) may be provided on another layer of flexible circuitry onthe same flexible connector (50), with both layers extending along acommon length of the flexible circuitry of the same flexible connector(50). As another merely illustrative example, dedicated traces for oneelectrode module (100) may be provided on the same layer of flexiblecircuitry as dedicated traces for another electrode module (100), suchthat the separate sets of traces are geometrically parallel on a commonlayer. In some other versions, different electrode modules (100) mayshare one or more common traces in a given flexible connector (50). Byway of example only, one or more traces in flexible circuitry offlexible connectors (50) may be used for bus transmissions, such thatinformation associated with different electrode modules (100) may becombined onto a bus and communicated along one or more non-dedicatedtraces that are in communication with more than one electrode module(100). Various other suitable ways in which traces or othercommunication features may be used, provided, arranged, etc., will beapparent to those of ordinary skill in the art in view of the teachingsherein.

Circuit board (130) in each electrode module (100) of the presentexample also comprises sensing circuitry (not shown), which includes anamplifier among other components. Such sensing circuitry is incommunication with connectors (134) of circuit board (130), such thatthe sensing circuitry may communicate with the one or more traces offlexible connectors (50). With the sensing circuitry of circuit board(130) including an amplifier in the present example, it should beunderstood that electrode modules (100) are thus active. Such sensingcircuitry may be configured and/or operable in accordance with theteachings of U.S. Pub. No. 2005/0215916, entitled “Active, MultiplexedDigital Electrodes for EEG, ECG, and EMG Applications,” published Sep.29, 2005, the disclosure of which is incorporated by reference herein;and/or in accordance with the teachings of any other document citedherein. Indeed, various ways in which the teachings herein may becombined with the teachings of U.S. Pub. No. 2005/0215916 and/or theteachings of any other document cited herein will be apparent to thoseof ordinary skill in the art. Alternatively, the sensing circuitry ofcircuit board (130) may have any other suitable configuration and/oroperability. For instance, some versions of circuit board (130) may lackan amplifier, such that electrode modules (100) are not active. Stillother suitable ways in which circuit board (130) may be configured,including but not limited to various forms and components of sensingcircuitry, will be apparent to those of ordinary skill in the art inview of the teachings herein.

In the present example, conductive ring (150) comprises a tail portion(152) that extends radially outwardly. Conductive ring (150) isconfigured to rest on annular rim (114) of lower clamshell member (104),with tail portion (152) projecting through trench (116) of lowerclamshell member (104). Accordingly, annular rim (114), trench (116),and tail portion (152) cooperate to assist in properly registeringconductive ring (150) with lower clamshell member (104) and assist insecuring conductive ring (150) relative to lower clamshell member (104).Of course, these features are just an example, and various otherstructures, features, techniques, etc. for registering and/or securingconductive ring (150) relative to lower clamshell member (104) will beapparent to those of ordinary skill in the art in view of the teachingsherein. As best seen in FIG. 7, upper clamshell member (102) ispositionable over conductive ring (150) to further secure conductivering (150) in place by “sandwiching” conductive ring (150) betweenclamshell members (102, 104). As noted above, a portion of conductivering (150) is still exposed in the inner diameter of the central opening(106) of the assembled electrode module (100) (e.g., when upperclamshell member (102) is secured to lower clamshell member (104),etc.). Conductive ring (150) is also communicatively coupled with thesensing circuitry of circuit board (130) (e.g., through contact via tailportion (152), etc.). In particular, conductive ring (150) is configuredto communicate ERP signals to the sensing circuitry of circuit board(130) as will be described in greater detail below.

Electrode modules (100) may be coupled with head frame (24) in a varietyof ways. In the present example, electrode modules (100) are coupledwith head frame (24) through snap fittings at snap members (28) of headframe (24). For instance, as shown in FIGS. 5-7, each electrode module(100) of the present example is provided with a snap adapter (170). Eachsnap adapter (170) comprises an upper flange (172), a lower flange(174), and a cylindraceous portion (176) extending vertically betweenupper and lower flanges (172, 174). Lower clamshell member (104)includes an annular recess (118) that is configured to snappinglyreceive upper flange (172) of snap adapter (170) as shown in FIG. 7.Snap adapter (170) thus couples with electrode module (100) through asnap fitting in the present example, though it should be understood thatany other suitable features, components, techniques, etc., may be usedto secure a snap adapter (170) with an electrode module (100).Alternatively, electrode module (100) may have an integral or unitarysnap adapter, or may couple with head frame (24) in some other way.

In the present example, a pad (160) is secured to each snap adapter(170). Each pad (160) has a plurality of outwardly extending tabs (162)and is relatively soft. For instance, the configuration of pad (160) mayreduce discomfort to a test subject when a clinician manipulateselectrode modules (100) while electrode modules (100) are on the testsubject's head. Pad (160) is configured to fit about cylindraceousportion (176) of snap adapter (170). As shown in FIG. 7, pad (160) is“sandwiched” between the lower surface of lower clamshell member (104)and the upper surface of lower flange (174). Of course, pad (160) may becoupled with electrode module (100) in a variety of other ways. By wayof example only, pad (160) may be secured to electrode module by one ormore clips, hook and loop fasteners, adhesives, etc. Alternatively, pad(160) may be omitted entirely. For instance, snap member (28) of headframe (24) may be positioned about cylindraceous portion (176) of snapadapter (170). Snap member (28) may thus be “sandwiched” between thelower surface of lower clamshell member (104) and the upper surface oflower flange (174), similar to pad (160) in FIG. 7. In the presentexample, however, snap adapter (170) snappingly engages with snap member(28) (e.g., such that at least a portion of snap member (28) ispositioned below lower flange (174)).

As yet another merely illustrative variation, snap adapter (170) maysimply be omitted. By way of example only, snap member (28) may itselfsnapplingly engage with lower clamshell member (104). For instance, snapmember (28) may include an outwardly extending annular flange that issnappingly received in annular recess (188) of lower clamshell member(104). As still another merely illustrative variation, electrode modules(100) may couple directly with head frame (24), such that no snapfittings are used to couple electrode modules (100) with head frame(24). By way of example only, electrode modules (100) may be coupledwith head frame (24) by one or more clips, hook and loop fasteners,adhesives, etc. In addition, while electrode modules (100) are removablycoupled with head frame (24) in the present example, electrode modules(100) may be permanently affixed to head frame (24) in some otherversions.

It should also be understood that when several snap member (28) (orother types of electrode module (100) engagement structures) andresilient straps (26) are arranged to provide a head frame (24), somesnap members (28) may not have a corresponding electrode module (100)coupled thereto. It should therefore be understood that some headsets(20) may be configured to accommodate different kinds of electrodesystems that have different numbers of and/or arrangements of electrodemodules (100), providing a degree of modularity. Still other suitableways in which electrode modules (100) may be incorporated into a headset(20) will be apparent to those of ordinary skill in the art in view ofthe teachings herein.

Exemplary Sensors

As shown in FIGS. 5 and 8-9, electrode system (10) of the presentexample further includes removable sensors (200). Removable sensors(200) of this example each comprise an insulating upper portion (202),an electrolytic hydro gel lower portion (204), and a conductive centerportion (206) positioned between upper and lower portions (202, 204).Conductive center portion (206) comprises a plurality of outwardlyextending conductive tabs (156). Each sensor (200) is configured to beinserted in the central opening (106) of a corresponding electrodemodule (100) and fit snugly therein. In some settings, each electrodemodule (100) in an electrode system (10) has an associated removablesensor (200) inserted therein; though some electrode modules (100) maylack an associated electrode module (100) in some settings. Inclinedsurface (108) of upper clamshell member (102) at the perimeter ofopening (106) may facilitate insertion of sensor (200) in opening (106),such as by guiding sensor (200) into opening. Of course, as with otherfeatures described herein, inclined surface (108) is merely optional,and may be modified, substituted, supplemented, or omitted as desired.

When removable sensor (200) is inserted in electrode module (100), andthe corresponding head frame (24) is secured to a test subject's head,removable sensor (200) is configured such that electrolytic hydrogellower portion (204) contacts the scalp of the test subject. Forinstance, sensor (200) may have a height such that hydrogel lowerportion (204) protrudes below lower flange (174) of snap adapter (170)while insulating upper portion (202) is vertically positioned at or nearinclined surface (108) of upper clamshell member (102). Alternatively,sensors (200) may have any other suitable dimensions. Furthermore,depending on the positioning of a given electrode module (100), theassociated electrolytic hydrogel lower portion (204) may contact someother part of the test subject's head or body. For instance, hydrogellower portion (204) may simply contact the hair on the test subject'shead; and electrode system (10) may still work properly even if sensors(200) only contact the hair on the test subject's head withoutnecessarily contacting the skin on the test patient's scalp. Due to theelectrolytic properties of the electrolytic hydrogel lower portion(204), electrolytic hydrogel lower portion (204) may pick up voltages orsignals (e.g., ERP signals, etc.) from the test subject's (e.g.,patient's) skin. Electrolytic hydrogel lower portion (204) may collectdata without needing to be pasted or glued to the test subject's head,as the hydrogel itself may sufficiently adhere to the subject's headwhile also allowing removable sensor (200) to be pulled away from thesubject's head with relative ease.

As noted above, tabs (208) of the present example are formed as unitaryextensions of a conductive member (206) that is disposed betweeninsulating upper portion (202) and electrolytic hydrogel lower portion(204). Conductive member (206) and tabs (208) are configured such thattabs (208) are resiliently biased to assume radially outwardly extendingorientations, as shown in FIGS. 5 and 8-9. It should be understood thatwhen sensor (200) is inserted in opening (106) of electrode module(100), tabs (208) contact conductive ring (150), which is exposed in theinner diameter of opening (106) as shown in FIG. 7. For instance, tabs(208) may resiliently bear against conductive ring (150) when sensor(200) is inserted in opening (106). Such contact between tabs (208) andconductive ring (150) may provide a path for communication fromconductive member (206) to conductive ring (150) as described in greaterdetail below. In addition, elastomeric properties or other properties ofinsulating upper portion (202) and/or hydrogel lower portion (204) mayhelp retain sensor (200) in opening (106) of electrode module. Inaddition or in the alternative, sensor (200) may be oversized relativeto opening (106), such that sensor (200) is snugly or interferingly fitin opening (106). Other ways in which sensor (200) may be substantiallyretained in opening (106) will be apparent to those of ordinary skill inthe art in view of the teachings herein.

Conductive member (206) and tabs (208) may be formed of silver-silverchloride and/or any other suitable material or materials. Conductivering (150) may also be formed of silver-silver chloride and/or any othersuitable material or materials. With conductive member (206) and tabs(208) being in direct contact with electrolytic hydrogel lower portion(204), it should be understood that voltages or signals that are pickedup by electrolytic hydrogel lower portion (204) may be furthercommunicated to and through tabs (208). With tabs (208) being in contactwith conductive ring (150) when sensor (100) is inserted in opening(106) of electrode module (100), tabs (208) may thus communicatevoltages or signals picked up by electrolytic hydrogel lower portion(204) to conductive ring (150), which may in turn communicate suchvoltages or signals to sensing circuitry of circuit board (130). Anamplifier on circuit board (130) (or elsewhere) may amplify the signal,and other components within the sensing circuitry may perform otherprocessing of the signal if desired, and the signal may then becommunicated away from electrode module (100) via flexible circuitry inone or more flexible connectors (50). The signals may thus ultimately becommunicated to control box interface module (30) via flexibleconnectors (50) and then on to control box (40) via cable (42).

In some versions, removable sensors (200) comprise HydroDot® DisposableEEG Electrodes or HydroDot® Biosensors by HydroDot, Inc, of Westford,Mass. Various aspects of the HydroDot® Disposable EEG ElectrodeApplication System are discussed in U.S. Pat. No. 5,479,934, entitled“EEG Headpiece with Disposable Electrodes and Apparatus and System andMethod for Use Therewith,” issued Jan. 2, 1996, which is incorporated byreference herein. Of course, various components of electrode system(10), including but not limited to removable sensors (200), may beconfigured, modified, and/or operable in accordance with any suitableteachings in U.S. Pat. No. 5,479,934. Indeed, various ways in which theteachings herein may be combined with the teachings of U.S. Pat. No.5,479,934 will be apparent to those of ordinary skill in the art. Itshould also be understood that removable sensors (200) are notnecessarily required in all versions. For instance, electrode modules(100) may be configured such that they have an electrical interface withthe test subject's head and/or some other type of interface with thetest subject's head and/or other body part through an injectable gel orin any other suitable fashion.

While sensors (200) of the present example have a substantiallycylindraceous shape, it should be understood that sensors (200) mayalternatively have any other shape. By way of example only, sensors(200) may have a cubical shape, a right cuboidal shape, a conical shape,a frustoconical shape, a pyramidal shape, a spherical shape, and/or anyother suitable shape. Similarly, while conductive rings (150) of thepresent example have a substantially circular shape, it should beunderstood that conductive rings (150) may alternatively have any othershape. By way of example only, conductive rings (150) may have a squareshape, a rectangular shape, a triangular shape, and/or any othersuitable shape. Still other suitable configurations of and relationshipsbetween sensors (200) and conductive rings (150) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

In the present example, electrode system (10) comprises eight electrodemodules (100). As another merely illustrative example, electrode system(10) may comprise twenty three electrode modules (100). Of course,electrode system (10) may alternatively comprise any other suitablenumber of electrode modules (100). It should also be understood thatelectrode modules (100) may be arranged in a variety of ways. By way ofexample only, various suitable arrangements are disclosed in thedocuments that are cited herein.

Signals obtained using electrode system (10) may be processed inaccordance with the teachings of U.S. Pub. No. 2008/0208072, entitled“Biopotential Waveform Data Fusion Analysis and Classification Method,”published Aug. 28, 2008, the disclosure of which is incorporated byreference herein and appended hereto. Alternatively, signals obtainedusing electrode system (10) may be processed in any other suitablefashion. In addition, various suitable ways in which electrode system(10) may be used (including but not limited to signal processing) aredisclosed in the various documents cited herein. Still other suitableways in which electrode system (10) may be used will be apparent tothose of ordinary skill in the art in view of the teachings herein. Itis contemplated that the teachings herein may be incorporated into orotherwise combined with the systems, components, and methods disclosedin the documents cited herein, in numerous ways. Suitable ways in whichthe teachings herein may be incorporated into or otherwise combined withthe teachings of the documents cited herein will be apparent to those ofordinary skill in the art in view of the teachings herein.

Other features of the present electrodes and system will be understoodby those of ordinary skill in the art in view of the teachings hereinand in the materials appended hereto. Furthermore, variousmodifications, substitutions, supplementations, etc. will be apparent tothose of ordinary skill in the art in view of the teachings herein andin the materials appended hereto. Having shown and described variousembodiments of the present invention, further adaptations of the methodsand systems described herein may be accomplished by appropriatemodifications by one of ordinary skill in the art without departing fromthe scope of the present invention. Several of such potentialmodifications have been mentioned, and others will be apparent to thoseskilled in the art. For instance, the examples, embodiments, geometries,materials, dimensions, ratios, steps, and the like discussed above areillustrative and are not required. Accordingly, the scope of the presentinvention should be considered in terms of claims that may be presented,and is understood not to be limited to the details of structure andoperation shown and described in the specification and drawings.

1-20. (canceled)
 21. An electrode system, comprising: (a) a plurality ofelectrode modules, wherein each of the plurality of electrode modulescomprises an electrode housing, wherein each electrode housing defines asubstantially central opening, wherein the portion of the electrodehousing that defines the substantially central opening forms an annularramp; (b) a plurality of flexible connectors coupled with the pluralityof electrode modules, wherein the flexible connectors comprise flexiblecircuitry configured to communicate signals from the electrode modules,wherein the flexible circuitry comprises traces formed on a flexiblesubstrate; and (c) a plurality of sensors, wherein each sensor of theplurality of sensors is configured to removably couple with acorresponding one of the plurality of electrode modules, wherein theplurality of electrode modules are configured to sense evoked responsepotentials from a test subject, wherein each sensor is furtherconfigured to communicate sensed evoked response potentials to theassociated electrode module.
 22. The electrode system of claim 21,wherein each sensor is positioned within the substantially centralopening of the associated electrode module.
 23. The electrode system ofclaim 22, wherein each electrode module further comprises a conductivering, wherein each conductive ring is substantially coaxial with thesubstantially central opening of the associated electrode module. 24.The electrode system of claim 23, wherein the conductive ring of eachelectrode module is at least partially exposed in an inner diameter ofthe substantially central opening defined by the electrode housing ofthe associated electrode module.
 25. The electrode system of claim 24,wherein each conducting ring comprises an outwardly extending tailconfigured to engage the electrode housing.
 26. The electrode system ofclaim 21, wherein the electrode housing comprises an upper clamshellmember and a lower clamshell member, wherein the upper clamshell memberand the lower clamshell member are configured to couple with each other.27. The electrode system of claim 21, wherein each of the plurality offlexible connectors has a bent shape extending upwards from theelectrode modules.
 28. The electrode system of claim 21, furthercomprising a headset having a headpiece, wherein the plurality ofelectrode modules are configured to extend from the headpiece.
 29. Theelectrode system of claim 28, further comprising a snap adapter portionconfigured to mechanically couple with the plurality of electrodemodules to the headset.
 30. The electrode system of claim 29, furthercomprising a pad sandwiched between the snap adapter portion and theplurality of electrode modules, wherein the pad has a cross-like shapedefining an opening extending therethrough.
 31. An electrode system,comprising: (a) a plurality of electrode modules; (b) a plurality offlexible connectors coupled with the plurality of electrode modules,wherein the flexible connectors comprise flexible circuitry configuredto communicate signals from the electrode modules, wherein the flexiblecircuitry comprises traces formed on a flexible substrate; and (c) aplurality of sensors, wherein each sensor of the plurality of sensors isconfigured to removably couple with a corresponding one of the pluralityof electrode modules, wherein the plurality of electrode modules areconfigured to sense evoked response potentials from a test subject,wherein each sensor is further configured to communicate sensed evokedresponse potentials to the associated electrode module, wherein eachsensor of the plurality of sensors comprises an upper portion, a lowerportion, and a conductive portion between the upper and lower portions,wherein a portion of the conductor portion extends outward relative tothe upper and lower portions.
 32. The electrode system of claim 31,wherein each of the electrode modules are configured to engage a snapadapter, wherein the snap adapter defines an adapter opening, whereineach of the plurality of sensors is positioned within the adapteropening.
 33. The electrode system of claim 32, wherein the snap adaptercomprises a lower flange, wherein the lower portion of each sensor ofthe plurality of sensors is configured to descend below the lowerflange.
 34. The electrode system of claim 31, further comprising acontrol box in communication with the electrode modules.
 35. Theelectrode system of claim 34, wherein the control box comprises astorage medium storing evoked response testing protocols and a processoroperable to execute evoked response testing via the electrode modules inaccordance with the stored evoked response testing protocols.
 36. Theelectrode system of claim 35, wherein the electrode modules are incommunication with the control box interface module via one or more ofthe flexible connectors, wherein the control box is in communicationwith the control box interface module via one or more cables.
 37. Anelectrode system comprising: (a) a plurality of electrode modules,wherein each of the electrode modules comprises a housing, wherein thehousing defines a housing opening extending therethrough; (b) aplurality of flexible connectors in communication with the plurality ofelectrode modules, wherein the flexible connectors comprise flexiblecircuitry configured to communicate signals from the electrode modules;(c) a plurality of circuit boards, wherein each of the plurality ofcircuit boards are contained within the housing, wherein each ofplurality of circuit boards defines a circuit opening extendingtherethrough, wherein each of the plurality of circuit boards arefurther in communication with the plurality of flexible connectors; and(D) a plurality of sensors in communication with the plurality ofelectrode modules, wherein each of the plurality of sensors comprises aninsulating upper portion, an electrolytic hydrogel lower portion, and aconductive portion between the upper and lower portions, wherein thehousing opening, the circuit opening, the upper portion, and the lowerportion are coaxially positioned.
 38. The electrode system of claim 37,further comprising a head frame, further comprising a plurality of snapadapters configured to couple the plurality of electrode modules to thehead frame.
 39. The electrode system of claim 38, wherein each of theplurality of sensors are configured to rest within the snap adapter. 40.The electrode system of claim 37, wherein each of the plurality ofcircuit boards comprises at least one amplifier.